今日更新:International Journal of Solids and Structures 1 篇,Journal of the Mechanics and Physics of Solids 1 篇,Thin-Walled Structures 5 篇
International Journal of Solids and Structures
Non-contact electromagnetic controlled metamaterial beams for low-frequency vibration suppression
Yu Sun, Haokai Zheng, Qiang Han, Chunlei Li
doi:10.1016/j.ijsolstr.2024.112667
用于低频振动抑制的非接触式电磁控制超材料梁
To address the challenge of suppressing extremely-low frequency vibration and noise in precision instruments and equipment, a novel non-contact metamaterial beams is proposed in this paper. The resonators of the metamaterial beams integrate negative stiffness mechanism and electromagnetic damping tuning system. Based on the magnetic dipole theory and the electromagnetic induction law, the mechanical model of magnetic resonator is established. The band structure and transmission spectrum of the metamaterial beams are obtained by transfer matrix method. Besides, the results of numerical simulations are used to verify the accuracy of theoretical results. The result shows that the negative stiffness can be controlled by nonlinear magnetic force among the magnets. Based on this mechanism, the bandgap frequency can be reduced to a minimum of 50Hz. Then, the method of combining electromagnetic damping and negative impedance circuit is proposed to form a tuning system which can reduce the initial frequency of the bandgap to 4Hz. Interestingly, the proposed bandgap control mechanism achieves the extremely-low bandgap while broadens the bandwith relatively, which overcomes the deficiency of traditional quasi-zero-stiffness metamaterials that reduce the bandgap frequency while causing the bandwidth to narrow. This study is expected to provide valuable ideas for the application of metamaterials in the field of low-frequency vibration and noise reduction.
Modeling storage particle delamination and electrolyte cracking in cathodes of solid state batteries
Tao Zhang, Marc Kamlah, Robert M. McMeeking
doi:10.1016/j.jmps.2024.105551
固态电池阴极中存储颗粒分层和电解液开裂的模拟
Interface delamination between storage particles and solid electrolytes contributes to greater impedance for Li transfer and capacity loss in solid-state batteries. Electrolyte cracking would cause degradation of the ionic or electronic conductivity of electrolytes. The occurrence of interface delamination and electrolyte cracking is commonly ascribed to mechanical stress, which evolves from inhomogeneous shrinkage and swelling of storage particles confined by the surrounding solid electrolytes when lithium is extracted or inserted. Here, a coupled model of Li diffusion, ionic conduction, interfacial reaction, mechanical stress and a phase field fracture approach is applied to investigate defect-initiated interface delamination and how cracks nucleate in electrolytes in a full 3D dynamical description for the first time. We find that unstable interface delamination is a very likely event during extraction. On the other hand, homogeneous delamination where the whole interface delaminates simultaneously, can happen for smaller interfacial defects with larger particle sizes and higher applied current densities. Larger interfacial defects delay the onset of delamination due to damage dependent interfacial reaction. More particle storage capacity can be utilized for smaller particle sizes and smaller interfacial defects prior to delamination. We further demonstrate electrolyte cracking can happen quite readily, and the electrolyte can break into several parts in only one insertion half cycle and even the appearance of full delamination.
Comparison of two progressive damage models for predicting low-velocity impact behavior of woven composites
Yogesh Kumar, Mohammad Rezasefat, Sandro C. Amico, Andrea Manes, Patricia I. Dolez, James D. Hogan
doi:10.1016/j.tws.2024.111611
两种预测编织复合材料低速冲击行为的渐进损伤模型的比较
This research focuses on comparing the two progressive damage models available in the explicit nonlinear finite element software LS-Dyna. To explore the prediction capabilities in terms of mechanical response and dominating failure modes in S2 glass woven composites, low velocity impact response at four different energies ranging from 27.9 J to 109.7 J were considered in this study. A macro-homogeneous solid element formulated finite element model was simulated to understand the response and failure mechanics in the laminate under low-velocity impact. The material modeling was carried out utilizing the MAT 55 and MAT 162 material models. An effort has been made for robust calibration of the various physical and non-physical parameters in both material cards for accurate predictions. The prediction capabilities of the models were then examined by comparing them against the experimental results, which fall within the deviation of ∼ 11%. The results show that MAT 162 yields a better resemblance with the damage morphology patterns and the delamination for the accounted impact zone, due to inclusion of strain-rate effect. Overall, this paper provides insight into the limitations and advantages of both material models, which establishes the route for the selection of the appropriate material model for simulating impact behavior in woven composites.
Surface effects on wave propagation in piezoelectric-piezomagnetic loosely bonded bilayer system using nonlocal theory of elasticity
Sudarshan Dhua, Subrata Mondal, Arpita Maji
doi:10.1016/j.tws.2024.111612
基于非局部弹性理论的压电-压电松散键合双层体系中波传播的表面效应
This study investigates nonlocal and surface effects on the dispersion behaviors of Shear horizontal (SH) waves in piezoelectric(PE)- piezomagnetic(PM) bilayer systems. The interface between these two layers is imperfectly bonded. The general governing equations are derived from the nonlocal magnetoelectroelastic (MEE) theory by adding an inherent length. The G-M model and generalized Younge–Laplace equations have been used to incorporate surface effects into the boundary conditions of the bilayer systems. The closed-form dispersion equation is obtained analytically for electrically open and magnetically short conditions. Numerical solutions are utilized to investigate the effects of nonlocal scale parameters and surface parameters on SH surface wave propagation. Contrary to the results of classical theory, the coupling effects of nonlocal small-scale and surface piezoelectricity are more significant than individual effects. Also, it has been observed that the imperfectness parameter across the interface and the thickness ratio of the bilayer significantly affect the phase velocity. Moreover, 2D and 3D plots of the mode shapes of field variables for the propagation of SH waves are presented graphically. These results are validated by conducting analyses excluding nonlocal effects. This allows us to isolate the specific impact of surface effects in the piezoelectric-piezomagnetic bilayer system, drawing connections to existing results and enhancing the robustness of our findings. This study provides valuable insights into complex wave dynamics, helping to optimize the performance and functionality of such smart composites in various engineering applications.
GLARE deformation in low-restraint state: tensile and bending behavior
Yao Wang, Xiaokai Ye, Chao Yang, Junzhe Wei, Sifa Zheng, Libin Zhao, Ning Hu
doi:10.1016/j.tws.2024.111613
低约束状态下的眩光变形:拉伸和弯曲行为
Fiber metal laminates (FMLs) possess a better weight reduction effect than traditional metal materials due to the coupling properties of heterogeneous materials, showing promise in the areas of aviation and aerospace. At present, the research on FMLs mainly focuses on the deformation properties after curing while the mechanical properties in the low-restraint state, i.e. the laminates are temporarily not cured and are formed under lower constraint stresses, are not studied in detail. Herein, the low-restraint GLARE is taken as a research object and its deformation characteristics and failure mode are studied using uniaxial tensile, bending experiments and numerical simulation in this paper. Moreover, the influence of key parameters, such as temperature, laminate structure and span length, is investigated, as well as the tensile and bending deformation behavior of GLARE in a low-restraint state is obtained. In addition, based on experimental observations, it is found that the low-restraint GLARE produces the phenomenon of interlayer slip, and the interlaminar residual stress is much smaller than the cured laminate, whereas the deformation limit and performance are improved. This paper provides theoretical bases for the in-depth analysis of deformation properties and forming laws of low-restraint GLARE, guiding further applications of laminates.
Dual-functional perforated metamaterial plate for amplified energy harvesting of both acoustic and flexural waves
Tian Deng, Luke Zhao, Feng Jin
doi:10.1016/j.tws.2024.111615
双功能穿孔超材料板,用于放大声波和弯曲波的能量收集
Metamaterials with defect states are commonly utilized in energy harvesting from acoustic and elastic waves due to their remarkable ability to localize waves. In this study, a novel piezoelectric energy harvester based on a perforated double-pillars metamaterial plate with a point defect, which offers the advantage of efficiently harvesting both ambient acoustic and flexural wave energy, is proposed. The proposed structure incorporates a locally resonant mechanism that enhances the concentration of vibration energy at the defect band frequency. Then, the amplified wave energy is efficiently converted into electrical energy by attaching a piezoelectric patch at the defect position. To initiate this investigation, the differential quadrature method is employed to theoretically estimate the boundary frequencies of the first band gap. Subsequently, this study investigates how holes size, electrical boundary conditions, and electrical circuit connections affect the energy harvesting of both acoustic and flexural waves. Correspondingly, the mechanisms behind their effects are thoroughly explained. Numerical results demonstrate that the wave energy localization performance can be remarkably amplified with an increasing holes radius, and the harvesters with the 1mm holes radius generate voltages that are approximately 2.12 and 1.44 times higher than those with the 0mm holes radius from acoustic and flexural waves, respectively. Furthermore, variations in the defect band frequency and corresponding wave localization behavior depend on the specific electrical boundary conditions and circuit connection approaches, ultimately leading to distinct results in the output electrical energy. These findings present valuable insights and guidelines for the development of high-performance electronic applications in the context of acoustic and elastic wave energy harvesting.
Aerodynamic Stability and Free Vibration of FGP-Reinforced Nano-Fillers Annular Sector Microplates Exposed to Supersonic Flow
Ehsan Arshid, Saeed Amir, Abbas Loghman, Ömer Civalek
doi:10.1016/j.tws.2024.111610
超声速流动下fgp增强纳米填料环形扇形微板的气动稳定性和自由振动
Metal foams have many different uses, but they also have some weaknesses. To address this issue, scientists are exploring the possibility of adding nano-fillers to make them stronger and more rigid. As a result, there has been increased interest in analyzing structures that are made from these materials among researchers. Here and now, the authors have conducted a new study that focuses on analyzing the aerodynamic stability and free vibrational characteristics of an annular sector microplate. This is the first time that such an analysis has been done for this type of microplate. The microplate is exposed to supersonic flow and nonlinear temperature changes. The actual properties of the microplate are determined via different introduced homogenization schemes; and four distinguished patterns for both pores and nano-fillers dispersion are considered. To evaluate the reinforcements impact, two most widely recognized nano-fillers, i.e., carbon nanotubes and graphene nanoplatelets are employed and their influence on the outcomes is observed. By utilizing Hamilton's principle and performing certain mathematical operations, the equations of motion were derived and solved numerically under different boundary conditions. A case study is conducted to examine how different parameters affect the natural frequencies, corresponding mode shapes, and critical aerodynamic pressures. Since no similar research has been found, the outcomes of this work may be accounted as reference points for upcoming investigations.